Added "inset-up, inset-down, inset-left, inset-right" four arguments to $direction
Added "inset-up, inset-down, inset-left, inset-right" four arguments to $direction

Please see http://codepen.io/P233/pen/AtzIw for more details.

jamadam/bourbon-docs-jp,greyhwndz/bourbon,chriseppstein/bourbon,nagyistoce/sass-bourbon.io,san650/bourbon,jamadam/bourbon-docs-jp,zyj1022/bourbon,jamesmenera/bourbon-libsass,nickg33/bourbon,jasonwalkow/bourbon,nickg33/bourbon,smithdamen/bourbon,ismarkunc/bourbon,jamadam/bourbon-docs-jp,Jazz-Man/bourbon,chriseppstein/bourbon,jamesmenera/bourbon-libsass,mindeavor/bourbon,smithdamen/bourbon,Jazz-Man/bourbon,zyj1022/bourbon,setie/bourbon,craftsmen/bourbon,Nikeshsuwal/bourbon,jasonwalkow/bourbon,cllns/bourbon,craftsmen/bourbon,thoughtbot/bourbon,setie/bourbon,thoughtbot/bourbon,mindeavor/bourbon,greyhwndz/bourbon,jamadam/bourbon-docs-jp